Apparatus for reproducing sound records



April 21, 1931. F. L. DYER APPARATUS FOR REPRODUCING SOUND RECORDS Filed Jan. 2, 1929 INVENTOR Patented A r. 21, 1931 ream: L. DYER, on NEW Yoax, 1v. Y.-

APPARATUS FOR REPRODUCING SOUND RECORDS Application filed January 2, 1929. Serial No. 329,800.

My invention relates to an improved appa-.

ratus for reproducing sound records intended particularly for use in motion picture theaties. The invention provides forthe repro- 5 duction of sound records intended to be operated in synchronism with a motion picture film audit also preferably comprises'means for reproducing from sound records independently of the film. Specifically and in its preferred form, the invention contemplates the use of a pair of turntables for receiving successive records which are intended to be reproduced in synchronism with the film 'b .through suitable electrical pick-up devices and preferably two other turntables on which ordinary sound records may be placed so as to furnish music or other entertainment in the intervals between the pictures or td fur-r nish music concurrently with the showing 'of i pictures and appropriate to the subject thereof. a

The invention is intended to supply a com pact, convenient andeasily operated apparatus which may be placed in the orchestra pit or in a separate booth for the purpose,.one of the objects of my invention being to produce an apparatus for the purpose which will not. require to be operated in the ordinary projection booth. When a sound reproducing apparatus is located and operated in the projection booth,the operator is required to work under very crowded conditions, in a more or less stifling atmosphere-and Where the noise is sometimes so great as to make it difficult for him to be assured that the sound reproduction is in fact in synchronism with the picture on the screen.

With my improved apparatus I am enabled to correct any lack of. synchronism between the picture and sound in a very simple and effective way. Under normal conditions, the turntables. carrying the records will rotate synchronously with the pro ection machine so that the film and sound record will exactly synchronize. This may be done by drivingthe projecting machine and the turntables by separate electric motors designed to run in synchronism as is well known in the art or instead the two motors 60 may be entirely independent but of constant the corresponding portion -spee'd up or slightly. lower speed type, the variation in speed between such motors in practice being negligible.

While therefore the projecting machine and talking machine will normally run in synchronism, yet it is important thatthere 55 shall be provided'some way by which the synchronous relation between the two may be restored if, for any reason, they should become non-synchronous. The latter conditionis very likely to occur due to the fact that the sound record may be started too soon or too late or sections of the film.may e removed without the similar removal of of the sound record.

Of course, there have been many suggestions heretofore made by which this correction can be effected, but so far as I know it has always been proposed to keep the sound record turning at a constant speed and to retard the projecting machine until the picture and record are synchronous. \Vhat I propose is to effect this control of the apparatus at the talking machine, be-

cause in this way the construction and opera tion can be materially simplified. What I therefore do is to provide normal driving means by which the normal synchronous relationship between the motor andthe turntables will be secured and to provide other dr ving means by which either turntable can be caused to operate at a speed either slightly belowor slightly above the normal speed. If, therefore, it is found that the sounds are lagging behind the film it becomes possible to instantly speed up the record until synchronism is secured and" after which the drive will return to. normal. On the other hand, if the sounds are in advance of the film, the record may be operated at a.

speed until synchronism is secured. By having the change above and below normal quite small, the chan e in pltch ofv the record will be impercepti le to the ordinary ear. I i

In order that this ;change in turntable nection between the synchronized records and the two at the right being intended for ordinary records, the electrical circuits being shown diagrammatlcally anda projecting machine being illustrated 33 in which is mounted a driving shaft 4.

in outline.

Figure 2 is a vertical sectional view of the parts of the machine at the left, showing more particularly the arrangement for changing the speed of the turntables before referred to. g

Figure 3 is a detailed view taken on the line 3-3 of Figure 2, looking in the direction of the arrow and illustrating the connection to the driven shaft for effecting low speed.

Figure 4 is a section on the line 44 of Fig-, ure 2, looking in the direction of the arrow, showing the connection to the driven shaft providing for normal speed.

Figure 5 is a section on the line 5-5 of Figure 2, looking in the direction of the arrow and showing the connection to the driven shaft for efiecting high speed.

Figure 6 is an enlarged section showing-the lower portion of the insulating panel carrying the contact rings.

In all of the above views corresponding )arts are represented by the same numerals.

A metal supportingplate 1 is carried on the upper portion of a suitable box or cabinet 2, said plate carrying the mechanical parts, whereby the plate may be removed to expose the mechanism. Depending from this plate 1, are a series of brackets 33,

This driving shaft is driven by an electric motor 5 through a worm 6 and gear 7. Said motor as shown is supported by the bed plate 1.

At the right of the machine are two turntables 8.8, the shafts 9 of which are driven at the desired speed from the driving shaft 4 through gears 10. These turntables are intended to receive ordinarytalking machine records which may be played during the intervals between films or they may furnish music of an appropriate character during the exhibition of the films. By having two turntables, a record may be placed on one while a record is beingplayed on the other, whereby a practically continuous musical performance may be secured. Any suitable means may be employed for starting and stopping these turntables.

The two turntables at the left 11-11 are intended to receive talking or musical records which are to be synchronized with the motion picture. I prefer to have these turntables rotate continuously and to provide means whereby the record on either of the turntables may be first held from rotation and then be released at the proper moment so as to be turned frictionally by the turntable.

Each of these turntables 11-11 is driven through gearing 13 from a driven shaft 14 as shown particularly in Figure 2.

The shaft 14 is driven from the. driving shaft 4 through three sets of gears 15-16 for effecting the low speed, 17-18 for efiecting the normal speed and 19-20 for effectin the high speed. The differences in speed a ove and below normal are very small so that the change in pitch of a musical selection will not be objectionable.

I have illustrated a desirable arrangement by which the gears 16, 18 and 20 may be connected to or disconnected from the shaft 14 and which at the same time secures a positive drive-for each speed. The three gears 16, 18 and 20 are loose on the shaft 14 and rotate in the direction of the arrows as shown in Figures 3, 4 and 5 respectively. Obviously the gear 16 moves somewhat slower than the gear 18 which in turn moves somewhat slower than the gear 20.

The gear 16 is preferably connected to the driven shaft 14 through a ratchet clutch of well known construction comprising a recessed member 21 and balls or rollers 22. If the gear 16 tends to turn faster than the shaft 14 the balls or rollers 22 will be pinched between the member 21 and the hub or ring 23 on said gear, whereby the gear will be positively connected to the shaft 14 so as to drive the same at the low speed. If, how-- ever, the shaft 14 tends to turn faster than the gear 16 (as when it is driven at normal or high speed) the balls or rollers 22 will be released, so that there will be no driving connection between the gear 16 and the driven shaft 14. Thedriving connection be tween the gear 16 and the shaft 14 automatically takes place when theconnections between gears 18 and 20 and said shaft are released V For the purpose of connecting and disconnecting the gear 18 from the shaft 14, I show in Figure 4 a ratchet 24 connected to shaft 14 adapted to be engaged by a pawl 25 on the gear 18. I illustrate a magnet 26 for actuating this pawl although obviously the pawl may be operated mechanically. A spring 27 normally holds the pawl 25 in engagement with the ratchet 24 so that the shaft 14 will thereby be drivenat normal speed. When the shaft 14 is thus driven the balls or rollers 22 at the low speed connection will I I shaft 14 takes 'highspeed is disconnected from the shaft 14.

desired speeds,

ple push buttons,

be unclutched. This normal driving of the 'placewhen the gear for order to effect the high speed drive of the shaft 14 I show in Figure 5 a ratchet 28 keyed to the shaft 14 and adapted to be engaged'by a pawl 29 on the high speed gear 20. This pawl 29 is normally held out of engagement with the ratchet 28 by a spring but is adapted to engage said ratchet b energizin engages t e ratchet 28 the shaft 14 will be driven at the required high speed, in which 1 low speed case the balls or rollers 22 at the will be disconnected and the pawl 25 will move backwards slowly over the ratchet 24 at the normal speed connection.

In .this way it will be seen that I utilize a positive drive for the turntables at the three while at the same time the arrangement is such that there can be no breaking or jamming of the'parts in the event of faulty operation. It will also be seen that when the magnets 26 and 31 are energized the turntables will be driven at normal speed since, as I have explained, the high speed pawl 29 from the ratchet 28. By energizing the magnet 31 so as to engage the pawl 29 with the ratchet 28 the shaft 14 will be turned at high speed. By energizing the magnet 26' supplying current to the magnets 26 and 31. Th

1s comprises an insulated panel 32 shown particularly in Figure 6, to both faces of which aresecured contact rings 3333 and 34-34. The brushes 3535 sweep around in contact with the rings 33-- 33 and brushes 36-36 for magnet 31 sweep around in contact with the rings 34-34. Current is. supplied to the two sets of rings from a common battery 37 shown in Figure 1. Two switches 38 and 39 are shown for energizin the magnets 26 and 31 respectively. hese switches are preferably simcause the turntables to rotate at slow speed while by closin ing it closed the turntables will rotate at high speed. When both push buttons are released the turntables rotate at normal speed. Evenif both push buttons are depressed sis multaneously there will be no breaking or jamming of partssincethis would simply result in the high speed connection.

As shown in Figure 1 there is a separate electric pick-up 40 for each turntable, said pick-ups being of any suitable type. They all feed into a common circuit 41 and to a suitable amplifier 42 b which the telephone currents will be ampli ed to the proper exis normally disengaged or magnet 26 so that the operator by clos- 'ing the circuit at, 38 and holding it closed will the circuit at 39 and hold- "shaft for rotating the turntable, of

l tent. These amplified currents actuate one or more loud speakers 43 located at any suitable point or points. single loud speaker 43 cone type.

Y I also show in Figure 1 the outline of a projecting machine 44 driven from an electric motor 45. The two motors 5 and 45 may be so-called synchronous motors, being of the conventional y interconnected so as to rotate at the same a magnet 31. When the pawl 29 speed or they may be independent motors each operating at .a constant speed. In the atter case any small variation in the speed of either motor may be corrected by the speed change mechanism above described.

aving now described my invention, what I claim as new therein and desire to secure by Letters Patent is as follows:

1. In a sound reproducing apparatus, the combination with a turntable and motor,'of gearing between providing a normal turntable speed, a second gearing between the turntable and, motor the turntable and motor I'showin Figure 1 a providing a slightlyhigher speed,and a third I gearing between providing a slightly lower speed.

2 In a sound reproducing apparatus, the combination with a turntable and a motor, of a driving shaft turned by the motor, a driven shaft connected with the turntable, and gearing between the driving and driven shafts providing for normal turntable speed and slightly higher and lower turntable speeds.

3. In a sound reproducing apparatus, the combination with a turntable and a motor, of a driving'shaft turned by the motor, a driven shaft fordriving the turntable, earing between the driving and driven shafts roviding for normal turntable speed, means 3 or connecting and disconnecting-said gearln'g from the driven shaft, gearing between the driving and driven shafts for a slower the turntables and motor turntable speed, and a friction connection I between the latter gearing and the driven shaft which becomes automatically operative when the normal gearing is disconnected from the driven shaft.

4. In a sound reproducing apparatus, the

combination of a turntable, a motor, a driving shaft turned by said motor and a driven gearing between the driving and driven shafts providing for normal turntable speed, means for connecting and disconnecting said gearing from the driven shaft, a second gearing between the driving and driven shafts providing a high turntable speed, and means for connecting the latter gearing to the driven shaft whereby the normal gearing automatically becomes ineffective.

5. In a sound reproducin apparatus, the combination with a turnta 1e, a motor, a driving shaft turned by the motor and a driven shaft for rotating the turntable, of

gearing between the driving and driven shafts providing for normal turntable speed, a ratchet and pawl connection between said gearing and the driven shaft, a second gearing between the driving and driven shafts providing for lower turntable speed, and a friction clutch between the latter gearing and the driven shaft whereby when the ratchet of the first named gearing is disengaged said friction clutch will connect the low speed gearing of the driven shaft.

6'. In a sound reproducing apparatus, the combination of a turntable, a motor, a driving shaft turned by said motor and a driven shaft for rotating the turntable, of gearing between the driving and driven shafts providing for normal turntable speed, a pawl and ratchet connection between said gearing and the driving shaft, a second gearing between the driving and driven shafts providing for high speed, and a pawl and ratchet connection between the second gearing and the driven shaft whereby the disengagement of the high speed pawl will permit the normal speed pawl automatically to drive the driven shaft, while the engagement of the high speed pawl will cause the normal speed pawl automatically to become ineffective. a Y

7. In a sound reproducing apparatus, the combination with a turntable, a motor, a driving shaft turned by the motor and a driven shaft for rotating the turntable, of

gearing between the driving and driven shafts providing for normal turntable speed,

a normally engaged ratchet and pawl, a connection between said gearing and the driven shaft, a second gearing between thedriving and driven shafts, providing for high turntable speed, and a normally disengaged ratchet and pawl connection between the second gearing and the driven shaft.

8. In a sound reproducing apparatus, the combination of two turntables and a single motor for driving them, of a single gearing between the motor and the two turntables providing for normal turntable speed, a second gearing between the motor and the two turntables providing for slightly lower speed and a third connection between the motor and the two turntables providing for slightly higher turntable speed.

FRANK L. DYER. 

